The aim of the proposed project is to test and replicate an emerging longitudinal social context model of the development of substance use and other problem behaviors during adolescence using existing databases and sophisticated analytic techniques. Within the theoretical model, peer influence and parenting deficits are hypothesized to be the two most important behavioral risk factors for the development of adolescent substance use and related problem behaviors. Such development is hypothesized to be influenced by the childrearing practices of the parents, and these practices are, in turn, thought to be influenced by family context factors such as intrafamilial conflict and parent substance use. The proposed project will use existing substance use databases to test a number of empirically derived models of the risk and protective factors contributing to the development of substance use and related problem behaviors in adolescence. A great deal of time and money has been expended to obtain excellent longitudinal data sets relevant to adolescent drug use, but many of these data sets have not been analyzed using state- of-the-art analytic techniques specifically designed for longitudinal data. In the proposed project, the validity of the developmental models will be evaluated through statistical methods designed to explore development and growth. Specifically, latent growth curve methodology, generalized linear modeling techniques, and hierarchical linear modeling will be employed to determine the influence of each of the antecedent risk and protective factors on development of substance use and other problem behaviors among adolescents. The structural relationships among these factors and their influence on the developmental process within the context of the hypothesized and other competing developmental models will be explored and compared. Tests of the theoretical model using different analytic techniques, and comparison of findings across datasets is likely to yield important information regarding adolescent substance use and other related problem behaviors that might otherwise go unexplored in these datasets.